The overall objectives of this investigation are to establish a model to study immunoprophylaxis and immunotherapy of lung cancer. To accomplsih this we are evaluating the effects of viable and nonviable preparations of Mycobacterium bovis (Strain BCG) on the latent period and incidence of benzo(a)pyrene induced bronchiogenic carcinoma in Syrian golden hamsters. We alre also studying the immunobiology of a transplantable lung tumor for the purpose of establishing a model for immunotherapy of lung metastasis. Companion studies will investigate the role of the alveolar macrophage in BCG immunotherapy of lung cancer. Results to date indicate that BCG may be of some value to control the development of bronchiogenic carcinoma.